Multimedia1: Vocal fold vibration during normal phonation from a top view.  An important feature of normal phonation is that the glottis remains closed for a considerable duration within one cycle of vocal fold vibration, which interrupts the glottal flow.  This periodic flow interruption is the main mechanism for harmonic sound production and regulation of voice quality.

Multimedia2: Audio of a breathy voice.

Multimedia3: Audio of a normal sounding voice.

Multimedia4: Audio of a pressed voice.

Multimedia5: Audio of a creaky voice / vocal fry.